SUMMARY/ABSTRACT The Nonhuman Primate Core (NHP Core) will function as a ?closed core? to provide NHP resources and technical support for three projects proposed in this NCTRI renewal. These projects are: Project I, Metabolic & Adipose Response (Roberts, Project Lead); Project II, Ovarian Structure & Function (Hennebold and Chavez, Co-Project Leads); Project III, Uterine & Placental Function (Slayden, Project Lead). The broad goal of this P50 NCTRI Center is to assess the independent and combined effects of testosterone (T) and a high-fat diet (typical of the ?Western-style diet?; WSD) on reproductive function and fertility. The specific goal of the NHP Core is to provide significant cost savings to the NCTRI Center projects. As part of the current NCTRI (years 01-05), the NHP Core leased and treated 39 peripubertal rhesus macaques with a controlled regimen of T, WSD and T+WSD for 5 years. The NHP core will continue to oversee treatments (years 06-07) for these animals and assist Projects I-III in sample collection. Shared use of the animals assigned to the core will eliminate repeated lease fees, and setup charges for the individual projects. The NHP Core will coordinate WSD treatment, thereby reducing per diem charges associated with the preparation of special diets. The NHP Core will provide a dedicated set of technical staff and management that would otherwise be cost-prohibitive for studies of this size. The NHP Core staff is trained to perform routine surgical and other procedures (e.g. T implant placement) that would otherwise require scheduling with the DCM Surgical Unit, greatly saving on procedural costs. After 7 years of WSD and T treatment, the animals will undergo treatment reversal in year 08. To fulfill the ultimate goal of the NCTRI center, the NHP Core will conduct fertility trials during treatment (year 06-07) and after treatment reversal (year 09). There will be no fee structure or chargebacks for Projects I- III. The NHP Core will provide general supplies (syringes, blood tubes, storage vials, swabs, etc.) leaving individual investigators responsible only for costs for procedures/assays unique to their particular projects. Researchers will plan studies with the NHP Core during regularly scheduled meetings between the core supervisor, Dr. Slayden, and NHP Core staff. The NHP Core will coordinate veterinary care and husbandry of the animals through the Oregon National Primate Research Center (ONPRC), Division of Comparative Medicine (DCM). NHP Core oversight will be provided by an Oversight Committee consisting of Dr. P. Kievit, Supervisor of the ONPRC Obese Animal Resource (Chair); Dr. H. Sidener; DCM clinical veterinarian, Dr. T. Hobbs, Head, DCM Surgery Unit, and Dr. C. True, NCTRI Co-investigator (Project I).